The Blazers, who trailed by as many as 21 points, closed within five in the third quarter, but Westbrook came back with consecutive jumpers and Oklahoma City went on to win 109-75 on Tuesday night.
"The home team will always make runs and my job as point guard is to take control of the game and not let things get out of whack," he said.
Westbrook finished with 32 points and eight assists to pace the Western Conference-leading Thunder to their fourth straight win. Kevin Durant scored 25 points and James Harden added 21 off the bench for the Thunder, who built a 65-47 lead by halftime.
"In the second [half] we were a little stagnant and we weren't getting any shots, so he just took it over," Kevin Durant said of Westbrook. "That's what great point guards do."
LaMarcus Aldridge had 20 points and eight rebounds as Portland fell to 3-4 under Kaleb Canales, who took over as interim coach when the Blazers fired Nate McMillan at the NBA trade deadline.
The Blazers were coming off a 90-87 victory over Golden State on Sunday. Portland has not had back-to-back wins since Jan. 23-24 against Sacramento and Memphis.
|More on Thunder-Trail Blazers|
|More NBA coverage|
"I don't think we made things as difficult as we could have," Aldridge said. "I feel like they were just taking warm-up shots in the first half."
The Thunder (38-12) were coming off a 103-87 victory at home over the Miami Heat on Sunday. Oklahoma City heads to Staples Center to face the Lakers on Thursday before hosting the Eastern Conference-leading Chicago Bulls on Sunday.
The Lakers defeated the Warriors 104-101 in Oakland on Tuesday night.
Smith is the son of the late Derek Smith, who played nine seasons in the NBA and was a close friend with Thunder coach Scott Brooks.
Brooks said before the game that Nolan Smith was the ring bearer at his wedding.
"He was a feisty little guy," Brooks said of the younger Smith, who went on to play at Duke before he was selected by the Blazers with the 21st overall pick in last June's draft.
Smith, who finished with three points in 25 minutes, said he felt he did well on defense, not so much on offense.
"There are things I definitely could do better. But it's a learning experience," he said. "Tomorrow I'll watch film and figure out how to get better."
The Thunder beat the Blazers 111-107 in overtime at the Rose Garden on Feb. 6, a game that was controversial because of a goaltending call on Aldridge in the final six seconds of regulation. The NBA overturned the call the next day.
Oklahoma City went up 28-14 on Derek Fisher's 3-pointer near the end of the first quarter. Fisher was playing his fourth game since he was picked up as a free agent by the Thunder last week.
The Thunder extended the lead to 57-40 midway through the second quarter on Westbrook's fast-break layup.
The Blazers narrowed it to 71-63 midway through the third quarter on Aldridge's turnaround jumper, putting the crowd on its feet for the first time in the game. Wesley Matthews added a 3-pointer, pulling Portland within five points, and Nicolas Batum raised his arms to the crowd on the way back down the court.
Westbrook's layup quieted the Rose Garden fans, but Aldridge hit his own to narrow it again for the Blazers. This time Westbrook answered with two straight jumpers.
Durant's 3-pointer a short time later extended the margin back out to 82-72 and the Thunder cruised the rest of the way.
"A lead of 20 in the first half is really nothing," Durant said. "A team like this is going to find a way to come back, and the crowd was unbelievable. They put pressure on us but we did a great job of responding."
J.J. Hickson, acquired by the Blazers last week after he was waived by Sacramento, had a season-high 21 points off the bench.
"Me coming here was kind of a blessing," Hickson said. "It was an opportunity."
- The Thunder's game Thursday against the Lakers marks Fisher's first game against his former team since the Lakers traded him to Houston earlier this month. The Rockets bought out his contract and he signed as a free agent with the Thunder last week.
- The Thunder always draw a number of fans wearing Seattle SuperSonics jerseys. One fan behind the Thunder bench had a sign that read "Stolen" with the Sonics' signature "S."
- Aldridge had a blocked shot to put him at 419 with the Blazers, tying him with Arvydas Sabonis for ninth on Portland's career list.